"That's a secret. You see," responded Zeph, looking duly wise and mysterious, "those boys were imported to this country by a peculiar old man, who wanted servants around him who weren't gabbing about his affairs and asking him questions all the time. Well, he's got them, hasn't he? I'm working for that man, or rather for a friend of his. Detective work," continued Zeph, rather proudly. "I've told Ralph. These two boys have been shut up in the house for two months. They just pined for fresh air, and trees--oh! trees are their stronghold. When I started out with them they made for the first tree like birds for a roost. I have taken them out for an airing, and I ran down here to report to Ralph how I was getting on, and brought them along with me for the novelty of the thing." "Do they live near here?" inquired Ralph. "No," answered Zeph, "we had to come by rail. I can't tell you where they live, but it's on a branch of the Great Northern. I've got to get back to-night. We've had our supper, Ralph. I just wanted to settle up the bills I owed you. I'll say good-bye to your mother and get to the depot." Zeph and his charges trooped to the kitchen door. Zeph spoke a few words to Mrs. Fairbanks. His companions bowed her a polite and graceful adieu, and Ralph accompanied their former boarder to the street. "See here, Ralph," said Zeph to the young engineer in parting, "I don't want you to think I wouldn't tell you everything." "That's all right, Zeph." "But honestly, I've solemnly agreed not to lisp a word about what I am really about or the people concerned in it." "That's all right, too," declared Ralph. "I'll say this, though," resumed Zeph: "I'm working on a strange and serious case. It's no play or fooling. I'm getting big pay. I may do a big thing in the end, and when I do, if I do, I'm coming straight to tell you all about it." Ralph watched Zeph and his charges disappear down the street with a great deal of curiosity and wonderment in his mind. A great many lively and unusual incidents were coming to the front recently, but this one was certainly enough out of the ordinary to give him food for profound thought. Ralph rejoined Fred in the garden, and took him into the house and introduced him to his mother. Mrs. Fairbanks won the heart of the manly young fellow, as she did the love of all of her son's friends. It was a pleasant, happy little coterie, that which sat down at the table soon afterwards to enjoy one of Mrs. Fairbanks' famous meals. "I'm ashamed!" declared Fred, after his seventh hot biscuit with freshly churned butter that made his mouth water, "but eating houses and hotels, Mrs. Fairbanks, make a roving, homeless fellow like me desperate, and if a third helping of that exquisite apple sauce isn't out of order, I'll have another small fish." "I'm spoiled for regular cooking, Bessie," declared Fogg to his wife. "Mrs. Fairbanks is fattening us till we'll be of no use at all."